Open data is essential to fight poverty, accelerate industry an innovation and reduce corruption, Internet inventor Sir Tim Berners-Lee said.
Speaking ahead of an open government summit in London, the 58-year old inventor urged governments and companies to make even sensitive information public.
"It is important that efforts to open up data and information are meaningful and lead to real change,” Sir Tim said.
Later today, he will present a report which found that while more than half (55 per cent) of 77 countries surveyed have open data policies in place, less than 10 per cent of key government data is available and truly open for re-use.
"Governments and companies must not shy away from publishing contentious datasets if they contain information that could be used to dramatically improve people's lives," said the scientists who launched the game-changing network on the Christmas Day of 1990.
The study also shows that the UK was the worldwide open data leader, followed by the US, Sweden, New Zealand and Denmark and Norway, who tied for fifth place.
It claims that controversial data such as company and land registers is among the least likely to be released, possibly due to a reluctance to drop lucrative access charges or hide politically sensitive information, or both.
The open data movement argues that information should be freely available for people to use and publish, without controls such as copyrights or patents.
It holds that "a piece of data is open if anyone is free to use, reuse, and redistribute it - subject only, at most, to the requirement to attribute and/or share-alike."
Detractors say that it raises concerns about privacy and the use of taxpayer money in costly data collection, "cleaning", management and dissemination.